“If it turns into a stand-off, Libya will become a cancerous cell”

You've just written a book. What is its thesis?It's a call to arms. We've globalised our economy and need to globalise our politics if we are not to end up with the most integrated but least governed world of any time in human history.

Do you believe the UN is fit for purpose?No. The picture I paint of a future international governance still has the UN as a platform, but is a more informal multinationalism where civil society gets things done.

Should France or Britain lose its seat on the Security Council?I would like to see that reopened, but it's not going to be. They realise what a privilege it is, relative to their global position, so Britain and France are the best UN citizens among the five.

What's your view of the resolution on Libya?I'm cautious, because it seems two rationales for intervention are being muddled. One is the humanitarian rationale of protecting civilians; the other is regime change. I would have preferred a clearer acknowledgement that Colonel Gaddafi poses a threat to peace and security, rather than the risk of creeping intervention.

What would you have done?As an old veteran, I like clarity. I like the legal justification, the political narrative and the military means to connect. There's a concern that this may not be the case here, and there's a real risk it could be too naked a western intervention in the affairs of an Arab country.

What's your reaction to the bombing campaign?It was the result of a very clever diplomatic fudge, which found words that everyone could agree with. For China and Russia and the abstainers, it was a ceiling, a limit to the action they would allow. For Britain and France, it was a floor, in terms of minimum action. Now, the diplomatic fracture lines are showing. Of course you had to pre-empt the killing of civilians in Benghazi; however, this is a military and diplomatic action with an awful lot of landmines buried within it.

What's your biggest worry?The prospect of a stalemate, with a divided Libya and the risk of no resolution. Look, there are two scenarios: the killing of civilians ends and Gaddafi falls at the hands of his own internal opponents, which then helps the wider Arab uprising. Or, it turns into a protracted stand-off and Libya becomes a cancerous cell. This second scenario has sufficiently high odds to mean that there is an imprudence about this venture. The risk this ends in a stand-off that slows the pace of change throughout the region and reopens old wounds between the west and the Arab world is high.

How do you think David Cameron has handled the Libya crisis?He's shown a resilience that people don't always attribute to him, particularly because it flies against his pragmatist, trade-led foreign policy. He's had to put up with more than his fair share of ridicule, so bravo to him for that. I think it is offset by the fact that it wasn't prudent to begin the speculation over the despatch box. It would have been better if it could have initially come from the Lebanese member of the Security Council, or from Turkey or Egypt.

What about William Hague?I think that some of what he's been blamed for is a little unfair. Britain can't always be the one speaking out, due to our history in the region. So he's had a bumpy few weeks - but as someone who's been a minister, I have a degree of sympathy for the situation that he finds himself in.

Did you get on with David Miliband?I got on fine with David. There was a tricky start. We did not know each other and he thought I had been parachuted in, but we became and remain great friends. I am not convinced that David is the guilty party, but I was briefed against and that was dismaying - these kinds of things tear into one's family life.

How was Gordon Brown as prime minister?On my own agenda of Africa, multilateralism and the G20, he and I were as one, but more broadly he was a fish out of water. He had huge difficulty managing the business of government and I found it to be very dysfunctional.

What's your response to reports that your bête noire, John Bolton, might run for US president?At one level, it is: "Bring it on." The only risk is that he will make Sarah Palin look like a decent candidate.

Is there a plan?No. There is the collectivity of lots of spontaneous actions by so many different people.

Is there anything you would like to forget?A lot. I would like to forget the humanitarian operations where we did not quite make it on time and lives were lost.

Are we all doomed?No. The whole theme of my writings is the extraordinary resilience of humankind.

Defining moments

1953 Born in South Africa1977 Becomes political correspondent at the Economist1994 Joins World Bank as director (later vice-president), external affairs2006 Is appointed United Nations deputy secretary general2007 Joins Gordon Brown's government as minister for Africa, Asia and the UN2011 Publishes his book The Unfinished Global Revolution